Jellyfish or medusa is the term used to describe the free-swimming stage of cnidarians. The vast majority of jellyfish species are marine inhabitants. Only a few species live as freshwater jellyfish in rivers and lakes. Their tentacles, which are covered with cnidocytes, are characteristic. The stinging cells burst on contact with the skin, injuring it with tiny stylet-like structures, and stinging venom penetrates the skin through the tiny injuries. Nettle venoms consist of a cocktail of different neurotoxins that, depending on the type of jellyfish, can cause mild burns to immediately life-threatening poisoning with respiratory paralysis and cardiac arrest. In the case of burns caused by poisonous jellyfish, it is important to know about the correct treatment.
How does a jellyfish sting make itself known?
So-called jellyfish stings, also known as jellyfish burns, are caused by burst nettle cells. The injuries are usually noticeable by burning and painful redness of the skin, which often develops into local swelling or even blisters that somewhat resemble burn blisters. Other systemic symptoms such as nausea with vomiting or circulatory collapse have also been observed, but are rare. In exceptional cases, the ingested neurotoxin may also cause disorientation and confusion. The process of “jellyfish sting” is completely passive and automatic when the stinging cells come into contact with the skin. This means that even the stinging cells of detached tentacles remain active for a longer period of time, as long as they are not completely dried out. Therefore, utmost caution is also required with washed up jellyfish or individual tentacles. Contact with any cnidocysts that may still be attached should be avoided as a precaution.
Four tips as first aid
If a jellyfish sting is from one of the species of jellyfish considered dangerous, the first two actions are to call an emergency physician and get out of the water as quickly as possible while being very careful and cautious. The next step is to rinse the affected skin areas with warm salt water. According to recent findings, in contrast to earlier recommendations, vinegar should not be used because vinegar does not slow down the activation of the hives, but actually increases it, so that up to 50 percent more toxin can be released.
Deglazing: Shaving foam or shaving gel
The main problem is often removing tentacle debris from the skin without bursting the cnidocytes that are still attached and making the situation worse. For some jellyfish species, such as the fire jellyfish, which is occasionally sighted on various stretches of the Mediterranean Sea, shaving cream forms an effective remedy. The visible tentacles are carefully sprayed with shaving foam. Only after the foam has dried can it be carefully scraped off together with the tentacles. If none of the above remedies are available, the attached tentacles can be covered with dry sand, which is then carefully removed again with the tentacles.
Carefully remove the tentacles from the body
Attempting to remove the tentacles from the skin after any of the suggested pretreatments should not be done with bare hands, but only with gloves. If gloves are not available, a towel can be used as an alternative. Knife backs, spatulas or similar objects have proven to be useful instruments for carefully scraping off the remaining tentacles. These should be passed over the skin at an angle of about 30 degrees. It is important that the object used has an edge that is not too sharp and can be used to remove the tentacles. If such objects are not available on the beach, a certain amount of creativity is required. For example, credit cards or membership cards in credit card format carried along can also be used.
Painkillers help
Stings from stinging jellyfish can be very painful. It is quite advisable to take painkillers such as ibuprofen or paracetamol, which are also prescribed for muscle and back pain, to reduce the pain symptomatically.
What you should avoid at all costs: Vinegar, fresh water, alcohol
Under no circumstances should fresh water (drinking water) or carbonated mineral water be used because, due to the osmotic pressure gradient, the hives, which are already under pressure, would absorb fresh water. Immediate bursting with the effect of further jellyfish stings would be the result. For the above reason, no alcohol or alcoholic beverage may be used to wash off the affected areas of the skin; only salt water may be used. As mentioned above, the earlier recommendation to rinse jellyfish burns with vinegar was absolutely counterproductive, because the vinegar does not inactivate the stinging cells, as was previously assumed, but actually increases the amount of venom they shoot. According to the latest scientific findings, therefore, vinegar should not be used under any circumstances, not even for stings by the highly poisonous box jellyfish or “sea wasp”. Earlier recommendations to treat jellyfish burns with human urine if necessary are also obviously no longer tenable.
Aftercare
After removal of all tentacles and their cnidocytes, the “burned” skin areas can be cleaned with warm fresh water and possibly protected from infection or mechanical irritation with compresses or a gauze dressing. Subsequent cooling with ice helps to contain pain and inflammatory reactions. To reduce itching and allergic reactions, antihistamines are recommended for external topical use and for internal systemic effects.
Inform about risk areas
Most jellyfish species that can be uncomfortable or dangerous to humans are ocean dwellers. However, ocean currents ensure that certain species wash up regularly or irregularly at certain times of the year, even near the coast, and swimmers are confronted with them. In most cases, the occurrence of the jellyfish is known, so that corresponding beach sections can be avoided. In the meantime, so-called stinger suits are also offered in Australia, which provide protection against the dangerous cube jellyfish and sea wasps, which mainly appear in Australian waters. Other inhabitants of tropical and subtropical seas are the Portuguese galley and the compass jellyfish. Even the Mediterranean Sea is not spared. There are mainly luminous jellyfish (Pelagia noctiluca) as well as hair jellyfish and compass jellyfish. Sporadically, the Portuguese galley (Phisalia physalis) has also been sighted in the Mediterranean, whose poisonous cocktail can cause serious damage, even cardiac arrest.